# V. AISC ASD - Square Tube Compression Capacity

Determine the axial compression capacity of a square 8x8x5/8 structural tube.

## Reference

AISC Allowable Stress Design, 9th Edition, tables on page 3-41.

## Problem

 Fy =46 ksi

 KyLy = KzLz = 25ft

## Comparison

The reported STAAD.Pro value is obtained by multiplying FA times AX from the STAAD.Pro output = 14.15(17.40) = 246.2.

Table 1. Comparison of results
Axial capacity (kips) 247 246.2 <1%

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\09 Steel Design\US\AISC\AISC ASD - Square Tube Compression Capacity.STD is typically installed with the program.

STAAD SPACE AISC VERIFICATION PROBLEM FOR AXIAL COMPRESSION CAPACITY.
START JOB INFORMATION
ENGINEER DATE 03-Sep-18
END JOB INFORMATION
* PAGE 3-41 OF 9TH ED. AISC-ASD. SQUARE TUBE 8X8X5/8, 25 FT LONG.
* FA SHOULD BE APPROX. 247/17.40 = 14.20 KSI
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 25 0;
MEMBER INCIDENCES
1 1 2;
START USER TABLE
TABLE 1
UNIT INCHES KIP
TUBE
TUB808010
17.4 8 8 0.625 153 153 258 7.48 7.48
END
UNIT FEET KIP
UNIT INCHES KIP
MEMBER PROPERTY
1 UPTABLE 1 TUB808010
*1 TA ST TUB808010
DEFINE MATERIAL START
ISOTROPIC STEEL_50_KSI
E 29000
POISSON 0.3
DENSITY 0.000283
ALPHA 6.5e-06
DAMP 0.03
TYPE STEEL
STRENGTH FY 50 FU 62 RY 1.5 RT 1.2
END DEFINE MATERIAL
UNIT FEET KIP
CONSTANTS
MATERIAL STEEL_50_KSI ALL
SUPPORTS
1 FIXED
2 FY -240
PERFORM ANALYSIS
UNIT INCHES KIP
PARAMETER 1
CODE AISC
FYLD 46 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH


                       STAAD.PRO CODE CHECKING - (AISC 9TH EDITION)   v1.0
********************************************
|--------------------------------------------------------------------------|
|                                                    Y        PROPERTIES   |
|*************                                       |        IN INCH UNIT |
|            *  |=============================|   |=====|     ------------ |
|MEMBER   1  *  |            UPT              |   |     |     AX =  17.40  |
|            *  | UP  TUB808010               |   |     |--Z  AY =   7.48  |
|DESIGN CODE *  |                             |   |     |     AZ =   7.48  |
| AISC-1989  *  ===============================   |=====|     SY =  38.25  |
|            *                                                SZ =  38.25  |
|            *  |&lt;---LENGTH (FT)=   25.00 --->|               RY =   2.97  |
|*************                                                RZ =   2.97  |
|                                                                          |
|                  0.0 (KIP-FEET)                                          |
|PARAMETER        |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  STRESSES     |
|IN KIP  INCH     |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  IN KIP  INCH |
|---------------  +L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  -------------|
| KL/R-Y= 101.17  |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  FA  =  14.15 |
| KL/R-Z= 101.17  +L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  fa  =  13.79 |
| UNL   = 300.00  |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  FCZ =  27.60 |
| CB    =   1.00  +L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  FTZ =  27.60 |
| CMY   =   0.85  |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  FCY =  27.60 |
| CMZ   =   0.85  +L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  FTY =  27.60 |
| FYLD  =  46.00  |L0 L0  L0  L0  L0  L0  L0  L0  L0  L0  L0  fbz =   0.00 |
| NSF   =   1.00  +---+---+---+---+---+---+---+---+---+---|   fby =   0.00 |
| DFF   =   0.00   0.0                                        Fey =  14.59 |
| dff=      0.00               ABSOLUTE MZ ENVELOPE           Fez =  14.59 |
| (KL/R)max = 101.17              (WITH LOAD NO.)             FV  =  18.40 |
|                                                             fv  =   0.00 |
|                                                                          |
|                      MAX FORCE/ MOMENT SUMMARY  (KIP-FEET)               |
|                      -------------------------                           |
|                                                                          |
|                AXIAL      SHEAR-Y    SHEAR-Z    MOMENT-Y    MOMENT-Z     |
|                                                                          |
|      VALUE     240.0         0.0        0.0         0.0         0.0      |
|   LOCATION       0.0         0.0        0.0         0.0         0.0      |
|                                                                          |
|**************************************************************************|
|*                                                                        *|
|*                         DESIGN SUMMARY  (KIP-FEET)                     *|
|*                         --------------                                 *|
|*                                                                        *|